1. Field of the Invention
A luggage roller.
2. Description of the Prior Art
In recent years it has been the practice to provide luggage, particularly large pieces of luggage which when loaded are quite heavy, with several rollers on their bottoms, e.g. two pairs or three pairs of rollers, whereby to enable a person to roll the luggage over flat surfaces without strain. Sometimes these rollers had fixed axes of rotation and in such event that axes of rotation were parallel to the bottom of the luggage and perpendicular to the length of the luggage. The axes of rotation of any pair of rollers conventionally were in registry. The rollers were ordinarily located near the sides of the luggage to obtain a large spacing between them. This was done because a loaded piece of luggage had a high center of gravity and tended to become unstable when tipped, or when subjected to a lateral force. By increasing the spaces between the rollers of a pair of rollers, stability was improved. It also has been proposed to provide the sundry rollers with swivel connections to the luggage, so that the direction of travel of luggage could be more easily altered.
Standard rollers, and by this reference is directed to the wheels as distinguished from the rotational mounting for the wheels, ordinarily have been provided with a cross section such that the roller has a laterally curved surface where it engaged the ground. It is believed that this was done in an effort to minimize friction between the wheel and the ground and this required less effort to pull or push the luggage; however because of this curved ground engaging surface, the distance between the points of contacts of two rollers of a pair of rollers was less than it effectively could be, so that the stability of the luggage using such wheels was somewhat low. It will be appreciated that a standard piece of luggage is not particularly wide; a specific width might be somewhere between 8 inches and 12 inches. A typical width between each wheel of a pair of roller wheels is about 6 inches from outside to outside; the actual spacing between the points of contact is only 51/2 inches so that if the center of gravity of a loaded piece of luggage is displaced by approximately 2 inches and 3/4 inches, the luggage will fall on its side. It would be highly advantageous if this effective spacing beween the extreme points of contact of the wheels and the ground could be increased.
Frequently debris, e.g. small pieces of wood or dirt or pebbles, will enter into the space between the wheel and a stationary part adjacent the wheel, for example a bracket that supports the wheel. This will prevent the wheel from rotating freely so that the wheel becomes fixed. With a jammed wheel the luggage becomes much more difficult to push or pull; in addition when a wheel jams and slides on the ground rather than rolls, the wheel becomes flat so that subsequently even if it is freed, it no longer will roll properly since the flat intermittently hits the ground.
Other times a wheel becomes damaged in a different fashion. For example, a wheel may split, or a journal for the wheel may become worn out. When a wheel becomes defective for any reason, it substantially destroys the piece of luggage for the person owning it. The roll-about feature is totally lost. The person has the choice of using the luggage without the roll-about feature, or fixing a wheel. In most cases since the mounting for the wheel, e.g. the bracket, is permanently connected to the piece of luggage, the replacement of the wheel is a major problem. A person must send the piece back to the manufacturer or to a special repair shop. More recently, it has been proposed to mount roller brackets on a plate which is detachably secured to a plate permanently fixed to the bottom of a piece of luggage. The theory is that a person of little skill can separate the two plates and buy a replacement plate with the wheel attached and substitute it for the plate having the defective wheel. However this practice has not been accepted by the public at large. They have purchased luggage with such detachable wheel brackets since it is a good sales feature while it is still in the store, but they have not taken advantage of this in everyday use. It would be highly desirable to provide a wheel which is replaceable with much greater ease than the structure utilizing detachable connecting plates. There is another problem which has plagued the roll-about luggage industry, namely that such luggage is difficult to roll about on floors covered with high pile carpeting including shag rugs. It would be desirable to provide a configuration of luggage wheel which is not susceptible to this drawback and which at the same time would provide greater stability and the ability to shed debris.